scholarly journals Dissecting the Prognostic Significance and Functional Role of Progranulin in Chronic Lymphocytic Leukemia

Cancers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 822 ◽  
Author(s):  
Lena Schulze-Edinghausen ◽  
Claudia Dürr ◽  
Selcen Öztürk ◽  
Manuela Zucknick ◽  
Axel Benner ◽  
...  

Chronic lymphocytic leukemia (CLL) is known for its strong dependency on the tumor microenvironment. We found progranulin (GRN), a protein that has been linked to inflammation and cancer, to be upregulated in the serum of CLL patients compared to healthy controls, and increased GRN levels to be associated with an increased hazard for disease progression and death. This raised the question of whether GRN is a functional driver of CLL. We observed that recombinant GRN did not directly affect viability, activation, or proliferation of primary CLL cells in vitro. However, GRN secretion was induced in co-cultures of CLL cells with stromal cells that enhanced CLL cell survival. Gene expression profiling and protein analyses revealed that primary mesenchymal stromal cells (MSCs) in co-culture with CLL cells acquire a cancer-associated fibroblast-like phenotype. Despite its upregulation in the co-cultures, GRN treatment of MSCs did not mimic this effect. To test the relevance of GRN for CLL in vivo, we made use of the Eμ-TCL1 CLL mouse model. As we detected strong GRN expression in myeloid cells, we performed adoptive transfer of Eμ-TCL1 leukemia cells to bone marrow chimeric Grn−/− mice that lack GRN in hematopoietic cells. Thereby, we observed that CLL-like disease developed comparable in Grn−/− chimeras and respective control mice. In conclusion, serum GRN is found to be strongly upregulated in CLL, which indicates potential use as a prognostic marker, but there is no evidence that elevated GRN functionally drives the disease.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3239-3239 ◽  
Author(s):  
Emilia Bialopiotrowicz ◽  
Patryk Gorniak ◽  
Bartosz Pula ◽  
Monika Noyszewska-Kania ◽  
Hanna Makuch-Lasica ◽  
...  

Abstract Lymph node microenvironment provides chronic lymphocytic leukemia (CLL) cells with pro-survival and protective signals, fostering resistance to conventional chemotherapeutics. CLL cells overexpress oncogenic PIM kinases, which modulate proteins engaged in transcription, translation, apoptosis, cell cycle and adhesion/motility (Mol Cancer Ther 2014, 13: 1231-45). Herein, we searched for the link between tumor microenvironment and PIMs expression, compared the clinical characteristics of CLL patients with high versus low expression of PIM kinases, and investigated the consequences of their inhibition with newly developed pan-PIM inhibitor, SEL24-B489 in primary CLL cells. We first evaluated the expression of PIM kinases in CD19+ cells derived from 88 newly diagnosed CLL cases. Patients with unmutated IGHV status exhibited significantly higher PIM1 transcript levels than patients with mutated IGHV genes. Subjects with advanced CLL (Binet C) exhibited higher PIM2 expression than patients in Binet A/B stage. Significantly higher PIM2 transcript abundance at the time of diagnosis was also observed in patients who relapsed after first line treatment (p=0.005). Expression of PIM2 and PIM3 kinases in lymph nodes was significantly higher than in peripheral blood, suggesting a relationship between PIM kinase expression/activity and CLL cell microenvironment. To further explore the role of microenvironment in the control of PIM expression, peripheral blood CLL cells were incubated with anti-IgM or CD40 ligand. Both stimuli induced PIM1 and PIM3 expression. Co-culture of CLL cells with stromal cell (HS5) monolayers promoted the expression of PIM3 isoform. We next assessed the consequences of PIM inhibition in CLL cells using novel pan-PIM inhibitor, SEL24-B489. Incubation with SEL24-B489 decreased phosphorylation of PIM substrates, p-FOXO1/3a(T24/T32) and p-4EBP1(S65), and induced dose-dependent apoptosis in 27 out of 28 analyzed cases, regardless of the IGHV mutation status and including relapsed patients. Of note, SEL24-B489 induced higher apoptotic response in primary CLL cells than referential pan-PIM inhibitor AZD1208. CLL cells with 17p13 deletion and obtained from chemo-refractory patients were also vulnerable to SEL24-B489, suggesting that functional p53 is not required for execution of SEL24-B489-mediated apoptosis. Importantly, SEL24-B489 was not toxic for cells derived from healthy donors. Since microenvironmental cues increase expression of PIM kinases, we hypothesized that interactions with stromal cells might hinder the in vitro activity of the PIM inhibitor. To explore this possibility, we compared apoptotic response to SEL24-B489 in CLL cells co-cultured on HS5 monolayers and CLL cells grown without the stromal support. In 6 out of 7 tested cases, SEL24-B489 overrode the protective signals from HS5 cells and induced apoptosis, although the cytotoxic effect of PIM inhibitor was stronger in the absence of stromal cells. PIM1 was shown to regulate CLL cells migration through CXCR4(S339) phosphorylation (Mol Cancer Ther 2014, 13: 1231-45). Accordingly, SEL24-B489 decreased phospho-CXCR4(S339), CXCR4 surface expression, and impaired CLL cells migration in the CXCL12 gradient. Surprisingly, decrease in the CXCR4 surface expression after SEL24-B489 was relatively modest when compared to the effect of this inhibitor on CXCL12-directed migration. We found that incubation of CLL cells with CXCL12 led to increase in the phosphorylation of mTOR(S2448) and Akt(S473). SEL24-B489 reduced the levels of p-mTOR(S2448), p-Akt(S473), p-4EBP1(T37/T46) and p-TSC2(S1798), revealing inhibitory effect on mTOR pathway. Pre-incubation of CLL cells with an mTOR inhibitor similarly restrained CXCL12-mediated mTOR activity and led to impaired CLL cells migration, uncovering the key role of mTOR axis in CXCR4-dependent migration. Thus, SEL24-B489 impairs the CLL cell migration by inhibiting CXCR4 surface expression and the CXCR4-triggered mTOR pathway. Taken together, we show that microenvironment signals increase expression of PIM kinases, supporting CLL cell survival and migration. Inhibition of PIM kinases impairs CXCR4-dependent migration and leads to CLL cells death, regardless of the p53 status. Targeting PIM kinases in CLL patients will likely release the cells from microenvironmental niches and might be a rational therapeutic strategy. Disclosures Warzocha: Novartis: Consultancy, Honoraria; BMS: Consultancy, Honoraria. Czardybon:Selvita S.A.: Employment. Galezowski:Selvita S.A.: Employment. Windak:Selvita S.A.: Employment. Brzozka:Selvita S.A.: Employment. Juszczynski:Selvita S.A.: Consultancy, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4134-4134
Author(s):  
Mirco di Marco ◽  
Serena Veschi ◽  
Rosa Visone ◽  
Giuseppe Leone ◽  
Paola Lanuti ◽  
...  

Abstract Clinical progression of chronic lymphocytic leukemia (CLL) is characterized by gradual reduction of the ratio T/B cells, along with immune cell dysfunction due, at least in part, to T cell defects, such as decreased expression of CD40L and reduced signaling via the TCR CD3. This compromise the ability of T cells to respond and to eliminate leukemic cell from CLL patients. Enhanced activation of either allogenic or autologous T cells can drive the death of CLL cells in vitro and in human subjects. Changes in microRNAs expression also characterize clinical progression of CLL with a strong decrease of miR-181b/a and miR-130a associated with the more aggressive phase of the disease. The miR-181b targets anti-apoptotic proteins, such as BCL-2 and MCL1 and its expression correlates with those protein levels in CLL. In this study we demonstrate that the expression of those microRNAs in CLL-B cells, are regulated by T cells. We co-cultured allogenic pure CLL-B cells with either activated (CD2, CD3 and CD28 antibodies, used to mimic antigen-presenting cells) or not activated CD4+ T cells from healthy donors. We observed a significant increase of mir-181b/a and miR-130a expression in CLL B-cells after co-culture with activated CD4+ T cells in 8 out of 11 cases. A significant increase of these miRs was also determined in purified CLL B-cells after 4 days activation of peripheral blood mononuclear cells (PBMCs) from CLL patients, even if in minor rate. By the use of specific antibodies, co-culture with Hela CD40 expressing cells and transwell experiments, we established that this effect is a T/B contact-dependent signaling mediated through CD40L-CD40 interaction. We determine that increased expression of the 3 miRs occurs at the transcriptional level. Since the expression of miR-181b showed the most significant variation in previous experiments it was selected for further analyses. We next investigated the in vivo role of the miR-181b in highly immunodeficient mice. The CLL cell line, MEC-01, infected with either the LV-miR-181b_coGFP or the LV-CTRL_coGFP was intravenously inoculated in NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice. Mice were sacrificed after 4 weeks and assayed for percentage of GFP+ cells in bone marrow and spleen compartments. The miR-181b did not show any specific effect into the leukemic clone. However when the same cells were inoculated in an environment hosting mature T cells, miR-181b consistently influences the death of leukemic cells (Fig 1B), suggesting that T cells are required to potentiate the apoptotic role of this miRNA. To explain what we observed in vivo, we mixed in vitro MEC-01 infected with either the LV-miR-181b or the LV-CTRL and CD8+ T cells from healthy donors. After few hours of contact T cells showed stronger cytotoxic effect on MEC-01 carrying miR-181b as compared to the control. Mixed lymphocyte reaction CD40L-activated CLL and T cells is used to generate effector CTLs. Therefore we grew T cell with CD40L-activated MEC-01 in which the expression of miR-181b was either shut down by lentiviral vector or unchanged as control. After one week, we monitored by cytofluorimetry the CD38 surface marker on T cells since its expression has been associated with more active CTLs and, by ELISA, the release of IL-10, the inhibitor of the potent inducer of CTLs INF-g. We demonstrate that activated MEC-01 with higher expression of miR-181b leads to an increase of the cell number expressing CD38 and this was accompanied by a reduced release of IL-10 from B cells through down-regulation of c-FOS, which we show to be target of the miR-181b and to promote the transcription of the IL-10. In conclusion, our data suggest a role of the miR-181b in the immune response against CLL-B cells. We show that an efficient activation of CD4+ T cells through CD3-complex pathway and a right CD40L-CD40 interaction lead to a significant increase of the some miRNAs deregulated over the progression of chronic lymphocytic leukemia, namely miR-181b. This miRNA potentiates the cytotoxicity of T cells favoring the killing of the leukemic clone. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2196-2196
Author(s):  
Ashima Shukla ◽  
Christine E Cutucache ◽  
Karan Rai ◽  
Siddharth Rai ◽  
Rene Opavsky ◽  
...  

Abstract Background: Chronic Lymphocytic Leukemia (CLL) is the most common adult leukemia in the United States. Clinical heterogeneity, a characteristic feature of CLL is a major problem in the clinical management of this currently incurable leukemia. We and others have demonstrated that the tissue microenvironment, specifically the lymph node (LN), influence the biological and clinical behavior including the clinical heterogeneity of CLL. Using gene expression profiling of CLL cells from peripheral blood (PB), bone marrow (BM) and LNs, we identified Cav-1 a member of the Tolerogenic Signature (genes associated with host immune tolerance) as one of the candidate genes which might be involved in the pathogenesis of CLL. We found that Cav-1 levels were significantly elevated (11 fold) in CLL cells from LNs compared to BM and PB. Cav-1 is the major element of caveolae, which are flask-shaped membrane invaginations. Cav-1 is involved in multiple cellular processes like the regulation and transportation of cellular cholesterol and lipids, clathrin independent endocytosis and signal transduction leading to oncogenesis or tumor suppression. We have previously shown that knock down of Cav-1 results in a significant decrease in cell migration and proliferation of primary human CLL cells in vitro. We have also demonstrated that knock down of Cav-1 prevents CLL cells from forming immune synapses. These immune synapses are important for the interaction between the CLL cells and their tumor microenvironment. These results suggest that Cav-1 protect CLL cells from undergoing apoptosis and enhances their migration in vitro. Objectives and Methodology: To understand the precise role of Cav-1 in leukemic progression in vivo, we crossed Cav-1-/- mice to Eµ-TCL1 mice, which is a well-established transgenic murine model for CLL. The offspring were observed and evaluated for the development of CLL. These mice were sacrificed at the age of 12, 24, 36 and 40+ weeks and peripheral blood, bone marrow and spleen and were examined for the presence of CD5+B220+CD19+ CLL cells using flow cytometry. Spleen, lymph nodes, liver, lungs and kidney were evaluated for the presence of CLL cells using H&E staining of histologic slides. Results: To study the role of Cav-1 in Eµ-TCL1, we isolated splenic B cells and measured the expression of Cav-1. We observed a gradual increase in the expression of Cav-1 in splenic B cells from Eµ-TCL1 mice at age of 12, 24 and 36 weeks when compared with wild type mice. This suggested that Cav-1 might be playing a role in CLL progression in Eµ-TCL1 mice. Therefore, to study the role of Cav-1 in CLL disease progression we decreased the expression of Cav-1 in vivo by breeding Eµ-TCL1 with Cav1 knockout mice. We generated Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice to study the effect of Cav-1 knock down in aggressiveness of CLL in vivo. We have shown that Cav-1 is overexpressed in CLL cells from patients with poorer clinical outcome and protects CLL cells from undergoing apoptosis. Therefore, we analyze the number of CLL cells in Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice. We observed a significant reduction in the number of B220+CD5+ CLL cells population in bone marrow and spleen of Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice when compared with Eµ-TCL1-Cav1wt/wt mice. We have previously shown that Cav-1 is important for CLL cells migration in vitro. Therefore, to study its effect in vivo we analyzed infiltration of CLL cells in spleen, lymph nodes, liver, kidney and lungs in these mice. There was no or significant decrease in tumor infiltration of CLL cells in spleen, lymph nodes, liver, lungs and kidney in Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice when compared with Eµ-TCL1-Cav1wt/wt alone. Next, we wanted to examine the effect of Cav-1 knock down on splenomegaly and hepatomegaly. We found that there was a significant decrease in splenomegaly and hepatomegaly in Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice. The spleen and liver size of Eµ-TCL1-Cav1-/+ and Eµ-TCL1-Cav1-/- mice was significantly reduced when compared with Eµ-TCL1 mice. Together these results suggest that high expression of Cav-1 in CLL cells leads to enhance proliferation and promotes disease progression in Eµ-TCL1 mice. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2021 ◽  
Author(s):  
Billy Michael Chelliah Jebaraj ◽  
Annika Müller ◽  
Rashmi Priyadharshini Dheenadayalan ◽  
Sascha Endres ◽  
Philipp M. Roessner ◽  
...  

Covalent Bruton tyrosine kinase (BTK) inhibitors such as ibrutinib have proven to be highly beneficial in the treatment of chronic lymphocytic leukemia (CLL). Interestingly, the off-target inhibition of IL-2-inducible T-cell kinase (ITK) by ibrutinib may also play a role in modulating the tumor microenvironment, potentially enhancing the treatment benefit. However, resistance to covalently binding BTK inhibitors can develop by a mutation in cysteine 481 of BTK (C481S), which prevents the irreversible binding of the drugs. In the present study we performed pre-clinical characterization of vecabrutinib, a next generation non-covalent BTK inhibitor, with ITK inhibitory properties similar to those of ibrutinib. Unlike ibrutinib and other covalent BTK inhibitors, vecabrutinib showed retention of the inhibitory effect on C481S BTK mutants in vitro, similar to that of wildtype BTK. In the murine Eµ-TCL1 adoptive transfer model, vecabrutinib reduced tumor burden and significantly improved survival. Vecabrutinib treatment led to a decrease in CD8+ effector and memory T-cell populations, while the naïve populations were increased. Of importance, vecabrutinib treatment significantly reduced frequency of regulatory CD4+ T-cells (Tregs) in vivo. Unlike ibrutinib, vecabrutinib treatment showed minimal adverse impact on activation and proliferation of isolated T-cells. Lastly, combination treatment of vecabrutinib with venetoclax was found to augment treatment efficacy, significantly improve survival and lead to favourable reprogramming of the microenvironment in the murine Eµ-TCL1 model. Thus, non-covalent BTK/ITK inhibitors such as vecabrutinib may be efficacious in C481S BTK mutant CLL, while preserving the T-cell immunomodulatory function of ibrutinib.


Blood ◽  
2004 ◽  
Vol 103 (12) ◽  
pp. 4389-4395 ◽  
Author(s):  
Freda K. Stevenson ◽  
Federico Caligaris-Cappio

Abstract The finding that chronic lymphocytic leukemia (CLL) consists of 2 clinical subsets, distinguished by the incidence of somatic mutations in the immunoglobulin (Ig) variable region (V) genes, has clearly linked prognosis to biology. Antigen encounter by the cell of origin is indicated in both subsets by selective but distinct expression of V genes, with evidence for continuing stimulation after transformation. The key to distinctive tumor behavior likely relates to the differential ability of the B-cell receptor (BCR) to respond. Both subsets may be undergoing low-level signaling in vivo, although analysis of blood cells limits knowledge of critical events in the tissue microenvironment. Analysis of signal competence in vitro reveals that unmutated CLL generally continues to respond, whereas mutated CLL is anergized. Differential responsiveness may reflect the increased ability of post-germinal center B cells to be triggered by antigen, leading to long-term anergy. This could minimize cell division in mutated CLL and account for prognostic differences. Unifying features of CLL include low responsiveness, expression of CD25, and production of immunosuppressive cytokines. These properties are reminiscent of regulatory T cells and suggest that the cell of origin of CLL might be a regulatory B cell. Continuing regulatory activity, mediated via autoantigen, could suppress Ig production and lead to disease-associated hypogammaglobulinemia. (Blood. 2004;103:4389-4395)


Blood ◽  
2016 ◽  
Vol 127 (5) ◽  
pp. 582-595 ◽  
Author(s):  
Marwan Kwok ◽  
Nicholas Davies ◽  
Angelo Agathanggelou ◽  
Edward Smith ◽  
Ceri Oldreive ◽  
...  

Key PointsATR inhibition is synthetically lethal to TP53- or ATM-defective CLL cells. ATR targeting induces selective cytotoxicity and chemosensitization in TP53- or ATM-defective CLL cells in vitro and in vivo.


Hematology ◽  
2011 ◽  
Vol 2011 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Jan A. Burger

Abstract Intrinsic factors such as genetic lesions, anti-apoptotic proteins, and aberrant signaling networks within leukemia cells have long been the main focus of chronic lymphocytic leukemia (CLL) research. However, over the past decade, it became increasingly clear that external signals from the leukemia microenvironment make pivotal contributions to disease progression in CLL and other B-cell malignancies. Consequently, increasing emphasis is now placed on exploring and targeting the CLL microenvironment. This review highlights critical cellular and molecular pathways of CLL-microenvironment cross-talk. In vitro and in vivo models for studying the CLL microenvironment are discussed, along with their use in searching for therapeutic targets and in drug testing. Clinically, CXCR4 antagonists and small-molecule antagonists of B cell receptor (BCR)-associated kinases (spleen tyrosine kinase [Syk], Bruton's tyrosine kinase [Btk], and PI3Kδ) are the most advanced drugs for targeting specific interactions between CLL cells and the miocroenvironment. Preclinical and first clinical evidence suggests that high-risk CLL patients can particularly benefit from these alternative agents. These findings indicate that interplay between leukemia-inherent and environmental factors, nature and nurture determines disease progression in CLL.


2018 ◽  
Vol 215 (2) ◽  
pp. 681-697 ◽  
Author(s):  
Erika Tissino ◽  
Dania Benedetti ◽  
Sarah E.M. Herman ◽  
Elisa ten Hacken ◽  
Inhye E. Ahn ◽  
...  

The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors.


1988 ◽  
Vol 80 (3) ◽  
pp. 129-133 ◽  
Author(s):  
Robert Schrek ◽  
William R. Best ◽  
Stefano Stefani

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